I had trouble with the FA 83 6" jumping crimp after 4 shots, but that short cylinder and lighter gun with to tight a tolerance fer this Bear Protection purpose,, in my opinion before I'm blasted. I did two things and eliminated it when using HOT 340 grain loads.
1st thing I did was turned the inside sizer button down on my RCBS dies.
2nd I then I ordered a Profile Crimp die.
3rd I then called Dan at Mountain Molds and used his software to build my own 340, with a WFN design, and an extra deep crimp groove. This bullet I also designed to barely clear the cylinder face on my Super Blackhawk, bisely hunter. Now from the looks of the crimp groove on the O/T 340's you showed I may not of needed to, but I enjoy casting my own, and I know I have as much powder room in my case as I can get using a boolit that will still fit in my Blackhawk in 45 colt.
Now I am glad I read this, as I am about to get a new 454 Alaskan. I thought about the Toklat with it's 5" barrel, as hideous as it looks with the flattend barrel look. But as was mentioned,, my intention is not just critter defense, but human defense as well. So the much faster, and easier, yet not rely easy to carry concealed, thank God I'm a big guy, the Alaskan is the only option.I will be using the MIHEC 270 grn SWC HP that I cast from pure lead with a tad of tin in it. in a 2.5 inch Bond Arms derringer with 6.0 grn red dot it only shot 650 fps but did this when recovered. I will have to bump that load in the Alaskan to get the same velocity and want 700 fps. But this is the results I want from it.
But this thread answers my question, the 454 loads will be capable of giving me the 1200 fps with the custom 340 I hard cast for serious dangerous game protection. and with my modified crimping actions should make it reliable.
I am taking the chance and not going with the even larger Toklat. Only time I will use it for dangerous situations is when I visit a buddy in north west Colorado, and make ky wilderness trips to the North of Michigan, an do a little hiking and hunting. When using it around home in the woods and hunting using it as my CCW and relying on it, any of my 45 colt loads should be all I need. This makes the Alaskan the better choice for me, and as others,, not just the grip on the Redhawk, but when it comes to the action, I prefer the Super also.